Highly sensitive fluorescent detection of p53 protein based on DNA functionalized Fe3O4 nanoparticles

Bioconjugates of photon-upconversion nanoparticles with antibodies for the detection of prostate-specific antigen and p53 in heterogeneous and homogeneous immunoassays

Sensitive immunoassays for the detection of tumor biomarkers play an important role in the early diagnosis and therapy of cancer. Using luminescent nanomaterials as labels can significantly improve immunoassay performance, especially in terms of sensitivity. Lanthanide-doped photon-upconversion nanoparticles (UCNPs) are nanocrystals capable of converting near-infrared radiation into visible light, and their emission spectra can be tuned by altering the dopant ions. In this study, the bioconjugation between UCNPs and biomolecules was optimized, and different conjugates of Er- and Tm-doped UCNPs (NaYF4:Yb3+,Er3+ and NaYF4:Yb3+,Tm3+) were prepared for detecting prostate-specific antigen (PSA) and tumor protein p53, comparing heterogeneous and homogeneous assay formats. The heterogeneous sandwich immunoassay achieved detection limits of 1.3 pg mL-1 for PSA and 330 pg mL-1 for p53. The homogeneous immunoassays were based on massively parallel spectroscopy (MPS), a novel artificial intelligence-aided single-molecule approach, utilizing conjugates of two different monoclonal antibodies with Er- and Tm-doped UCNPs, respectively. The conjugates provide distinct emission spectra, with only sandwich immunocomplexes of analytes and both types of labels showing signals at the same location. MPS was suitable for observing the immunocomplexes in an aqueous dispersion using only a small sample volume. This innovative method achieved detection limits of 8.2 ng mL-1 and 390 pg mL-1 for PSA and p53, respectively. MPS eliminates the need for time-consuming washing steps required in heterogeneous immunoassays and is amenable to high-throughput applications.

Immobilization-free and label-free electrochemical DNA biosensing based on target-stimulated release of redox reporter and its catalytic redox recycling

Herein, we demonstrate a simple, homogenous and label-free electrochemical biosensing system for sensitive nucleic acid detection based on target-responsive porous materials and nuclease-triggered target recycling amplification. The Fe(CN)63- reporter was firstly sealed into the pores of Fe3O4 nanoparticles by probe DNA. Target DNA recognition triggered the controllable release of Fe(CN)63- for the redox reaction with the electron mediator of methylene blue enriched in the dodecanethiol assembled electrode and thereby generating electrochemical signal. The exonuclease III (Exo III)-assisted target recycling and the catalytic redox recycling between Fe(CN)63- and methylene blue contributed for the enhanced signal response toward target recognition. The low detection limit toward target was obtained as 478 fM and 1.6 pM, respectively, by square wave voltammetry and cyclic voltammetry methods. It also possessed a well-discrimination ability toward mismatched strands and high tolerance to complex sample matrix. The coupling of bio-gated porous nanoparticles, nuclease-assisted target amplification and catalytic redox recycling afforded the sensing system with well-controllable signal responses, sensitive and selective DNA detection, and good stability, reusability and reproducibility. It thus opens a new avenue toward the development of simple but sensitive electrochemical biosensing platform.

Carboxyethylsilanetriol-Coated Magnetic Nanoparticles as an Ultrasensitive Immunoplatform for Electrochemical Magnetosensing of Cotinine

In the present study, an innovative and simple electrochemical magneto biosensor based on carboxyethylsilanetriol-modified iron oxide (Fe3O4) magnetic nanoparticles was designed for ultrasensitive and specific analysis of cotinine, an important marker of smoking. Anticotinine antibodies were covalently immobilized on carboxylic acid-modified magnetic nanoparticles, and the cotinine-specific magnetic nanoparticles created a specific surface on the working electrode surface. The use of magnetic nanoparticles as an immobilization platform for antibodies provided a large surface area for antibody attachment and increased sensitivity. In addition, the advantages of the new immobilization platform were reusing the working electrode numerous times, recording repeatable and reproducible signals, and reducing the necessary volume of biomolecules. The specific interaction between cotinine and cotinine-specific antibody-attached magnetic nanoparticles restricted the electron transfer of the redox probe and changed the impedimetric response of the electrode correlated to the concentration of cotinine. The magneto biosensor had a wide detection range (2-300 pg/mL), a low LOD (606 fg/mL), and an acceptable recovery (97.24-105.31%) in real samples. In addition, the current biosensor's measurement results were in good agreement with those found by the standard liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA) methods. These results showed that a simple impedimetric immunosensing platform was generated for the cotinine analysis.

A functional nucleic acid-based fluorescence sensing platform based on DNA supersandwich nanowires and cation exchange reaction

Accurate and sensitive analysis of p53 DNA is important for early diagnosis of cancer. In this work, a fluorescence sensing system based on DNA supersandwich nanowires and cation exchange (CX)-triggered multiplex signal amplification was constructed for the detection of p53 DNA. In the presence of p53 DNA, the DNA self-assembles to form a DNA supersandwich nanowire that generates long double-stranded DNA. Subsequently, the cation exchange (CX) reaction between ZnS and Ag+ was utilized to release free Zn2+. With the participation of Zn2+, DNAzyme catalyzes the hydrolysis of numerous catalytic molecular beacons, resulting in a greatly enhanced fluorescence signal due to the cycling of DNAzyme. The fluorescence values increased in proportion to the concentrations of p53 DNA in the range of 10 pM to 200 nM, and a detection limit (LOD) of 2.34 pM (S/N = 3) was obtained. This method provides an effective strategy for the quantitative detection of p53 DNA.

Recent Progress in Biosensors for Detection of Tumor Biomarkers

Cancer is a leading cause of death worldwide, with an increasing mortality rate over the past years. The early detection of cancer contributes to early diagnosis and subsequent treatment. How to detect early cancer has become one of the hot research directions of cancer. Tumor biomarkers, biochemical parameters for reflecting cancer occurrence and progression have caused much attention in cancer early detection. Due to high sensitivity, convenience and low cost, biosensors have been largely developed to detect tumor biomarkers. This review describes the application of various biosensors in detecting tumor markers. Firstly, several typical tumor makers, such as neuron-specific enolase (NSE), carcinoembryonic antigen (CEA), prostate-specific antigen (PSA), squamous cell carcinoma antigen (SCCA), carbohydrate, antigen19-9 (CA19-9) and tumor suppressor p53 (TP53), which may be helpful for early cancer detection in the clinic, are briefly described. Then, various biosensors, mainly focusing on electrochemical biosensors, optical biosensors, photoelectrochemical biosensors, piezoelectric biosensors and aptamer sensors, are discussed. Specifically, the operation principles of biosensors, nanomaterials used in biosensors and the application of biosensors in tumor marker detection have been comprehensively reviewed and provided. Lastly, the challenges and prospects for developing effective biosensors for early cancer diagnosis are discussed.

Biosensors and Drug Delivery in Oncotheranostics Using Inorganic Synthetic and Biogenic Magnetic Nanoparticles

Magnetic nanocarriers have attracted attention in translational oncology due to their ability to be employed both for tumor diagnostics and therapy. This review summarizes data on applications of synthetic and biogenic magnetic nanoparticles (MNPs) in oncological theranostics and related areas. The basics of both types of MNPs including synthesis approaches, structure, and physicochemical properties are discussed. The properties of synthetic MNPs and biogenic MNPs are compared with regard to their antitumor therapeutic efficiency, diagnostic potential, biocompatibility, and cellular toxicity. The comparative analysis demonstrates that both synthetic and biogenic MNPs could be efficiently used for cancer theranostics, including biosensorics and drug delivery. At the same time, reduced toxicity of biogenic particles was noted, which makes them advantageous for in vivo applications, such as drug delivery, or MRI imaging of tumors. Adaptability to surface modification based on natural biochemical processes is also noted, as well as good compatibility with tumor cells and proliferation in them. Advances in the bionanotechnology field should lead to the implementation of MNPs in clinical trials.

Advances with metal oxide-based nanoparticles as MDR metastatic breast cancer therapeutics and diagnostics

Metal oxide nanoparticles have attracted increased attention due to their emerging applications in cancer detection and therapy. This study envisioned to highlight the great potential of metal oxide NPs due to their interesting properties including high payload, response to magnetic field, affluence of surface modification to overcome biological barriers, and biocompatibility. Mammogram, ultrasound, X-ray computed tomography (CT), MRI, positron emission tomography (PET), optical or fluorescence imaging are used for breast imaging. Drug-loaded metal oxide nanoparticle delivered to the breast cancer cells leads to higher drug uptake. Thus, enhanced the cytotoxicity to target cells compared to free drug. The drug loaded metal oxide nanoparticle formulations hold great promise to enhance efficacy of breast cancer therapy including multidrug resistant (MDR) and metastatic breast cancers. Various metal oxides including magnetic metal oxides and magnetosomes are of current interests to explore cancer drug delivery and diagnostic efficacy especially for metastatic breast cancer. Metal oxide-based nanocarrier formulations are promising for their usage in drug delivery and release to breast cancer cells, cancer diagnosis and their clinical translations.

Biomarker targeted therapy approaches for TNBC using metal oxide-based NPs are highly effective and promising.

Nucleic Acid Tests for Clinical Translation

Nucleic acids, including deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), are natural biopolymers composed of nucleotides that store, transmit, and express genetic information. Overexpressed or underexpressed as well as mutated nucleic acids have been implicated in many diseases. Therefore, nucleic acid tests (NATs) are extremely important. Inspired by intracellular DNA replication and RNA transcription, in vitro NATs have been extensively developed to improve the detection specificity, sensitivity, and simplicity. The principles of NATs can be in general classified into three categories: nucleic acid hybridization, thermal-cycle or isothermal amplification, and signal amplification. Driven by pressing needs in clinical diagnosis and prevention of infectious diseases, NATs have evolved to be a rapidly advancing field. During the past ten years, an explosive increase of research interest in both basic research and clinical translation has been witnessed. In this review, we aim to provide comprehensive coverage of the progress to analyze nucleic acids, use nucleic acids as recognition probes, construct detection devices based on nucleic acids, and utilize nucleic acids in clinical diagnosis and other important fields. We also discuss the new frontiers in the field and the challenges to be addressed.

High-Fidelity and Simultaneous Sensing of Endogenous Mutant and Wild p53 Proteins for Precise Cancer Diagnosis and Drug Screening

The simultaneous sensing of endogenous wild and mutant proteins plays a critical role in disease diagnosis and drug screening, and this remains a major current challenge. Here, we present a new and highly specific target-triggered dual proximity ligation assay (dPLA) strategy for sensitive and simultaneous sensing of wild and mutant p53 proteins from cancer cells. Two proximity DNA probes bind the target protein to form the primer/circular DNA template complexes with two nicks in the presence of the hairpin and ssDNA connector sequences via the strand displacement reaction. Only when the two nicks are simultaneously ligated can the rolling circle amplification be triggered with high fidelity for yielding substantially enhanced fluorescence. By encoding the hairpin sequence, two distinct fluorescence signals can be generated for simultaneous detection of the wild and mutant p53 proteins. Importantly, our method significantly reduces the possibility of nonspecific ligation reactions by using two ligation nicks, which minimizes the background noise. With this dPLA method, the regulation transition of intracellular mutant p53 to wild p53 proteins upon anticancer drug treatment has also been demonstrated, highlighting its usefulness for potential early disease diagnosis and drug screening with high fidelity.

Biosensing platform on ferrite magnetic nanoparticles: Synthesis, functionalization, mechanism and applications

Ferrite magnetic nanoparticles (FMNPs) are gaining popularity to design biosensors for high-performance clinical diagnosis. The fusion of information shows that FMNPs based biosensors require well-tuned FMNPs as detection probes to produce large and specific biological signals with minimal non-specific binding. Nevertheless, there is a noticeable lacuna of information to solve the issues related to suitable synthesis route, particle size reduction, functionalization, sensitivity towards targeted intercellular biological tiny particles, and lower signal-to-noise ratio. Therefore it allows exploring unique characteristics of FMNPs to design a suitable sensing device for intracellular measurements and diseases detection. This review focuses on the extensively used synthesis routes, their advantages and limitations, crystalline structure, functionalization, along with recent applications of FMNPs in biosensors, taking into consideration their analytical figures of merit and range of linearity. This work also addresses the current progress, key factors for sensitivity, selectivity and productivity improvement along with the challenges, future trends and perspectives of FMNPs based biosensors.

Biosensor-based diagnostic approaches for various cellular biomarkers of breast cancer: A comprehensive review

Breast cancer is the most commonly occurring cancer among women which leads to thousands of deaths worldwide. The chances of survival are more if the breast cancer is diagnosed at early stage. At present, mammography, magnetic resonance imaging, ultrasound and tissue biopsies are the main diagnostic techniques available for the detection of breast cancer. However, despite of offering promising results, requirement of expensive setup, skilled supervision, expert analysis, invasive procedure (biopsy) and low capacity of multiplexing are the main limitations of these diagnostic techniques. Due to high cost, these screening tests are out of reach of people belonging to low socioeconomic groups and this poses serious health burden to the society. Recently, biosensor-based diagnostic technology for early detection of various types of cancers and other non-oncological disorders have gained considerable attention because of their several advantageous features over existing diagnostic technologies such as high throughput, noninvasive nature, cost effectiveness, easy interpretable results and capacity for multiplexing. Further, biosensors can be designed for biomarkers which are confined to particular type of cancer. In this review, we have discussed about various genomic, transcriptomic, proteomic and metabolomic biomarkers associated with breast cancer, various biosensors-based diagnostic approaches designed for detection of specific biomarkers associated with breast cancer are also described. Further, this review throws insight on various biomarkers linked with breast cancer which can be effectively exploited to develop new diagnostic technology. The assessment of these biomarkers associated with BC using biosensors in large population are cost-effective, non-invasive and high throughput. They help in risk assessment of disease at very initial stage even in backward areas and also help to lower the disease burden of society and economic cost of treatment for a common man. This review would provide new avenues for the development of biosensor based diagnostic technology for the detection of biomarkers associated with breast cancer.

Modification-free amperometric biosensor for the detection of wild-type p53 protein based on the in situ formation of silver nanoparticle networks for signal amplification

Sensitive and accurate quantification of wild-type p53 protein is of great importance for biological research and clinical diagnosis. Herein, a modification-free amperometric biosensor was proposed for sensitive detection of wild-type p53 protein by the signal amplification of silver nanoparticles (AgNPs) networks formed in situ on electrode surface. Double-stranded DNA (dsDNA) probe containing two consensus sites was immobilized on gold electrode surface to capture wild-type p53 protein. The cysteine thiol and amine groups on the exterior of the protein allowed for the attachment of bare AgNPs through the AgS or AgN interactions. Meanwhile, benzene-1,4-dithiol (BDT) molecules in solution triggered the assembly of more AgNPs on electrode surface through the AgS interactions, thus leading to the in situ formation of AgNPs networks for signal amplification. The target at the concentration as low as 0.1 pM can be readily determined. This method was further applied to determine wild-type p53 protein in spiked human serum and cell lysates with satisfactory results. Moreover, the biosensor is regenerative and does not require the modification of AgNPs with recognition element for signal readout. The modification-free strategy can potentially be applied to develop novel biosensors for detection of other biological macromolecules.

Implication of Magnetic Nanoparticles in Cancer Detection, Screening and Treatment

During the last few decades, magnetic nanoparticles have been evaluated as promising materials in the field of cancer detection, screening, and treatment. Early diagnosis and screening of cancer may be achieved using magnetic nanoparticles either within the magnetic resonance imaging technique and/or sensing systems. These sensors are designed to selectively detect specific biomarkers, compounds that can be related to the onset or evolution of cancer, during and after the treatment of this widespread disease. Some of the particular properties of magnetic nanoparticles are extensively exploited in cancer therapy as drug delivery agents to selectively target the envisaged location by tailored in vivo manipulation using an external magnetic field. Furthermore, individualized treatment with antineoplastic drugs may be combined with magnetic resonance imaging to achieve an efficient therapy. This review summarizes the studies about the implications of magnetic nanoparticles in cancer diagnosis, treatment and drug delivery as well as prospects for future development and challenges of magnetic nanoparticles in the field of oncology.

‘Off–on’ switchable fluorescent probe for prompt and cost-efficient detection of bacteria

The rapid and straightforward detection of bacteria in food and human samples is becoming important, particularly in view of the development of point-of-care devices and lab-on-a-chip tools for prevention and treatment of bacterial infections.